1. Field of the Invention
The invention relates to a closure device for a container having a neck, and also to a method of mounting such a device, and to a container fitted with such a device.
2. Description of the Related Art
In the field of containers for medication, it is known to use a glass vial for conserving an active principle in the form of a freeze-dried lyophilisate, a powders, or a liquid solution. Such a vial needs to be closed in sealed manner so as to keep its content in a satisfactory state of conservation until the time it is used. In order to close a vial hermetically, it is known to use a closure device that comprises an elastomer stopper having the function of being completely leaktight against gas, liquids and bacteria, a capsule made of metal, usually aluminum, that provides a sealing function, and a “flip-off” tongue that performs a tamperproofing indicator function and that needs to be removed before it is possible to gain access to the stopper.
When the metal capsule is crimped onto the top portion of a glass vial, it is possible for particles of glass to become detached from the vial, which particles can drop onto the top of the stopper and constitute a risk of polluting the content. In addition, the metal capsule is not crimped on immediately after the stopper has been put into place, regardless of whether the content of the vial has or has not been subjected to a freeze-drying stage. The time interval between putting the stopper into place and putting the capsule into place can be quite long since it is not unusual for the machine for crimping the capsule to be located in premises distinct from the premises where the content of the vial is sterilized, said distinct premises generally not being sterile. During this time interval, it is therefore possible for the content of the vial to be contaminated, whether accidentally or maliciously. When the vial is used, hospital staff are supposed, after removing the tamperproofing tongue, to decontaminate the top face of the stopper that becomes accessible through the opening formed in the capsule. That operation is sometimes forgotten, thereby likewise leading to a risk of contamination.
US-A-5 314 084 discloses using an outer cover for locking an inner cover into position on the neck of a container in order to protect a stopper. That mode of locking relies on the elasticity of the outer cover and is not always effective.